Hi. Thanks for your query. Noted the history of 18 weeks and 4 days pregnancy, had constipation so far, but loose stools since last 3 days, frequency is 3 per day, softer than before, wants to know whether this is OK... As per the history mild looseness along with frequency of 3 per day looks to be due to intolerance to something unusual you must have taken. But as a precaution send the stool sample for tests and if infection is present get a course of fetus-safe antibiotic, otherwise nothing to worry about. Try to identify the foods and beverages or something like nuts that can cause such a problem and stop altogether. Maintain hydration. Consult your Gynecologist if required.